[Mr_Brown]

I have been practicing shutdowns recently at the NDAC. Mostly doing them at 10-15m, after a 40 min dive in about 8 degrees, when your hands are starting to feel the cold, am now looking to increase the depth.

Is this advised when looking to do the TDI advanced Trimix... (what depth do they have you, do your shutdowns and within what timescales. 30 sec's 1 min? )

I suppose you should be compedent at doing them at any stage during the dive but just want to know what YOU all think.